Question

Find (f ° g)(0). *

f(x) = 5x – 4
g(x) = x^2 – 1

O A.3
OB. -9
O c.-4
O D.-17

Answer 1

B

Explanation:

Remark

I have to represent f(x) as plus +f(x)

I like to show this situation as +f(g(x)) which I think is much clearer.

+f(x) = 5x - 4

Solution

+f(g(x)) = 5(g(x)) - 4 What has happened is that wherever you see an x on the right you put in g(x).

Now on the right, you put whatever g(x) is equal to.

+f(g(x)) = 5(x^2 - 1) - 4

Remove the brackets.

+f(g(x)) = 5x^2 - 5 - 4

And make x = 0

+f(g(0)) = 5*0 - 5 - 4

+f(g(0)) = - 9